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At least 325 records · Page 18Linked to original sources
PubMed2006

Variance in neurocognitive performance is associated with dysbindin-1 in schizophrenia: a preliminary study.

Susceptibility genes for schizophrenia have been hypothesised to mediate liability for the disorder at least partly by influencing cognitive performance. We investigated the association between genotype and cognitive performance for a Dysbindin risk haplotype which is associated with schizophrenia in our sample. Fifty-two patients with schizophrenia or schizoaffective disorder (24 risk haplotypes carriers versus 28 non-risk haplotype carriers) were assessed in areas of cognition showing evidence of familial deficits in schizophrenia. Verbal and spatial memory, working memory, and attentional control was assessed using selected measures from the Weschler memory scale (WMS), Cambridge automated test battery (CANTAB), continuous performance test (CPT), and a simple go/no-go task. Pre-morbid IQ was also assessed using the Weschler Test of Adult Reading (WTAR). Patients carrying the Dysbindin risk haplotype showed significantly lower spatial working memory performance than patients who were non-risk carriers, with genotype explaining 12% of variance in performance. Our study suggests that the increased risk for schizophrenia associated with dysbindin may be partly mediated by its influence on pre-frontal function.

Adolescent↗
PubMed2006

Performance of galanin transgenic mice in the 5-choice serial reaction time attentional task.

The neuropeptide galanin impairs learning and memory in rodents. The mechanism underlying the cognitive effects of galanin may be related to inhibitory effects of galanin on cholinergic transmission. As cholinergic function is thought to modulate sustained attention, the present study examined whether galanin-overexpressing transgenic mice have impairments in sustained attention. Galanin transgenic (GAL-tg) mice and wild-type (WT) littermate controls were trained in a 5-choice serial reaction time task, modified to assess sustained attention. GAL-tg and WT mice performed similarly during acquisition with respect to accuracy, total omissions, and response speed. Attentional mechanisms were challenged by parametric changes including increased event rate, event asynchrony, or decreased stimulus duration. Singly, these challenges did not differentially affect performance between genotypes. Concurrent administration of these challenges, which represents an optimal test of sustained attention, also had similar effects on GAL-tg and WT mice. When stimulus discriminability was reduced by constant illumination of the house light, GAL-tg mice omitted more trials than WT mice, but other measures of performance did not differ by genotype. Moreover, intraventricular injection of galanin in WT mice did not affect sustained attention. These data indicate that previously reported learning and memory effects of galanin are not secondary to attentional dysfunction.

Acetylcholine↗
PubMed2004

Are genetic polymorphisms in OGG1, XRCC1 and XRCC3 genes predictive for the DNA strand break repair phenotype and genotoxicity in workers exposed to low dose ionising radiations?

Identification of higher risk individuals carrying genetic polymorphisms responsible for reduced DNA repair capacity has substantial preventive implications as these individuals could be targeted for cancer prevention. We have conducted a study to assess the predictivity of the OGG1, XRCC1 and XRCC3 genotypes and the in vitro single strand break repair phenotype for the induction of genotoxic effects. At the population level, a significant contribution of the OGG1 genotypes to the in vitro DNA strand break repair capacity was found. At an individual level, the OGG1 variants Ser/Cys and Cys/Cys genotypes showed a slower in vitro DNA repair than the Ser/Ser OGG1genotype. A multivariate analysis performed with genotypes, age, cumulative dose, exposure status and smoking as independent variables indicated that in the control population, repair capacity is influenced by age and OGG1 polymorphisms. In the exposed population, DNA damage is greater in older men and in smokers. Repair capacity is slower in individuals with Ser/Cys or Cys/Cys OGG1 genotypes compared to those with the Ser/Ser OGG1 genotype. Micronuclei (MN) frequencies increased with age and the cumulative dose of gamma-rays. Analysis of the total population revealed that genetic polymorphisms in XRCC1 resulted in higher residual DNA (RDNA) values and the Met/Met variant of XRCC3 resulted in an increased frequency of micronuclei. The analysis confirms that MN frequencies are reliable biomarkers for the assessment of genetic effects in workers exposed to ionising radiation (IR). A combined analysis of the three genotypes, OGG1, XRCC1 and XRCC3 polymorphisms is advised in order to assess individual susceptibility to ionising radiation. As an alternative or complement, the in vitro DNA strand break repair phenotype which integrates several repair pathways is recommended. Smokers with OGG1 polymorphisms who are exposed to ionising radiation represent a specific population requiring closer medical surveillance because of their increased mutagenic/carcinogenic risk.

Base Sequence↗
PubMed2004

Investigation of transcription factor AP-2 beta genotype in women with premenstrual dysphoric disorder.

It has repeatedly been shown that the serotonergic system is involved in the symptomatology of premenstrual dysphoric disorder (PMDD). Women with PMDD are reported to differ from symptom-free controls with regard to serotonin-related biological markers. Evidence from family and twin studies suggests a genetic contribution to the aetiology of PMDD. The expression of human transcription factor AP-2beta in neural crest cell lineages and neuroectodermal cells suggests that this protein may be of importance for functional characteristics of neurons by regulating the expression of target genes. Within the monoaminergic systems, several genes have binding sites for AP-2beta in regulatory regions, suggesting an involvement of AP-2beta in these systems. The gene encoding AP-2beta is located on chromosome 6p12-p21.1 and includes a polymorphic region consisting of a variable number of [CAAA] repeats located in the second intron. We have earlier shown that AP-2beta genotype is associated with serotonergic phenotypes and that brainstem levels of AP-2beta correlate positively to serotonin metabolism in rat frontal cortex. The aim of this study was to investigate the relationship between PMDD and transcription factor AP-2beta genotype. The participants included 176 women with PMDD and 91 healthy controls. Genotyping was performed by polymerase chain reactions. We did not observe any differences in AP-2beta genotype frequencies between PMDD subjects and controls. Our results suggest that AP-2beta genotype is not a risk factor for PMDD. To our knowledge, this is the first study investigating transcription factor AP-2beta genotype in women with PMDD. Hence, these results should be considered preliminary until replicated.

Adolescent↗
PubMed2005

Association of the genetic polymorphisms of the renin-angiotensin system with kidney graft long-term outcome: preliminary results.

Recent studies have demonstrated some association between the renin-angiotensin system (RAS) activity and the development and progression of different entities as diabetes mellitus (DM) or chronic allograft nephropathy. To investigate these associations, we studied some gene polymorphisms of RAS in a group of renal transplant recipients. We retrospectively analyzed 42 patients who underwent a primary renal transplantation for 2 years. A subgroup of 23 patients (55%) was diagnosed with postransplant DM in accordance with American Diabetes Association 2001 criteria. We studied two RAS gene polymorphisms: the angiotensin-converting enzyme insertion/deletion (ACE I/D) and angiotensinogen (AGTM235T). Genotyping was performed by DNA purification and amplification with a polymerase chain reaction technique. The distributions of genotypes were ACE DD, ID, II: 33%, 48%, 19%; and AGT TT, MT, MM: 15%, 45%, 40%, respectively. We observed a progressive loss in renal function measured by creatinine clearance (Cockroft) in D-allele carriers (DD+ID) between the first and the second transplantation year: 65.3 +/- 4.3 vs 59.8 +/- 4.6 mL/min (P = 0.02); that was not seen in II patients: 68.8 +/- 4.6 vs 68.4 +/- 4 mL/min (P = 0.87). Fifty percent of D-allele carriers developed DM vs 25% of non-D-allele carriers (P = 0.19). Eighty-three percent of homozygous patients for the AGT-TT allele developed DM vs 35% of non TT patients (P = 0.04). There were no significant differences regarding recipient demographic characteristics, type of donor, number and severity of acute rejections, and immunosuppressant treatment between the groups. In conclusion, ACE D-allele seems to be associated with a poorer kidney graft long-term outcome. ACE D and AGT T alleles may be implicated in glucose metabolism disorders after transplantation.

DNA↗
PubMed2000

Animal propagation and genomic survey of a genotype 1 isolate of Cryptosporidium parvum.

Human cryptosporidiosis is attributed to two major Cryptosporidium parvum genotypes of which type 1 appears to be the predominant. Most laboratory investigations however are performed using genotype 2 isolates, the only type which readily infects laboratory animals. So far type 1 has only been identified in humans and primates. A type 1 isolate, obtained from an individual with HIV and cryptosporidiosis, was successfully adapted to propagate in gnotobiotic piglets. Genotypic characterization of oocyst DNA from this isolate using multiple restriction fragment length polymorphisms, a genotype-specific PCR marker, and direct sequence analysis of two polymorphic loci confirmed that this isolate, designated NEMC1, is indeed type 1. No changes in the genetic profile were identified during multiple passages in piglets. In contrast, the time period between infection and onset of fecal oocyst shedding, an indicator of adaptation, decreased with increasing number of passages. Consistent with other type 1 isolates, NEMC1 failed to infect mice. A preliminary survey of the NEMC1 genome covering approximately 2% of the genome and encompassing 200 kb of unique sequence showed an average similarity of approximately 95% between type 1 and 2 sequences. Twenty-four percent of the NEMC1 sequences were homologous to previously determined genotype 2 C. parvum sequences. To our knowledge, this is the first successful serial propagation of genotype 1 in animals, which should facilitate characterization of the unique features of this human pathogen.

Animals↗
PubMed2000

Aldehyde dehydrogenase 2 and glutathione S-transferase M 1 polymorphisms in relation to the risk for oral cancer in Japanese drinkers.

We investigated 191 patients with oral cancer (121 males and 70 females) and 121 non oral cancer patients (69 males and 52 females), both groups with a history of alcohol use. Blood was analyzed with aldehyde dehydrogenase 2 (ALDH 2) and glutathione S-transferase M 1 (GSTM 1) genotyping. ALDH 2 genotyping was performed by polymerase chain reaction (PCR)-Restriction fragment length polymorphism (RFLP) method and GSTM 1 genotyping was amplified with PCR using GSTM 1 specific primers. In the oral cancer group, the alcohol-drinking rate (59.7%) was significantly higher than in the non cancer group (alcohol-drinking rate 27.3%, p < 0.01). The incidence of inactive ALDH 2 and GSTM 1 in the cancer group with an alcohol-drinking habit was 34.2 and 67.5% and was higher than in the non cancer group with an alcohol-drinking habit (15.1, 45.5%).

Adult↗
PubMed2004

Effects of serotonin transporter promoter polymorphisms on serotonin function.

The serotonin transporter promoter polymorphism (5-HTTLPR) has been associated with vulnerability to stress-induced depressive symptoms and with the speed and rate of response to antidepressant treatment. The goal of the present study was to evaluate the association between the 5-HTTLPR and the functional response of the serotonin system as measured by the neuroendocrine and cerebral metabolic response to intravenous administration of the selective serotonin reuptake inhibitor citalopram in normal control subjects. Genotyping was performed for 5-HTTLPR insertion/deletion polymorphism long (l) and short (s) variant alleles. The ll genotype was compared with the combined sl+ss and with the ss genotype alone. Citalopram plasma concentrations did not differ significantly between groups. The s allele was associated with a less of an increase in prolactin and cortisol than the ll genotype. The s allele was associated with greater decreases in left frontal, precentral and middle temporal gyri compared to the ll genotype. The ll genotype was associated with greater decreases in right frontal, insula and superior temporal gyrus compared to the ss genotype. These findings suggest that 5-HTTLPR is associated with an altered functional response of the serotonin system, which may represent a neurobiologic substrate for the differential response to antidepressant treatment in late life and the emergence of neuropsychiatric symptoms in neurodegenerative disorders.

Adult↗
PubMed2003

Association between polymorphisms in caspase recruitment domain containing protein 15 and allergy in two German populations.

BACKGROUND: Early exposure to microbial matter such as LPS may influence the development of asthma and allergies by activation of innate immunity pathways as indicated by studies in farming environments. Recently, polymorphisms in caspase recruitment domain containing protein 15 (CARD15), an intracellular LPS receptor protein, have been associated with Crohn's disease. Because these polymorphisms lead to changes in LPS recognition, they may affect the development of asthma and allergies. OBJECTIVE: We genotyped a large population of German schoolchildren (N = 1872) from East and West Germany for 3 functional relevant CARD15 polymorphisms for their role in the development of asthma and allergy. METHODS: By use of parental questionnaires, skin prick testing, pulmonary function tests, bronchial challenge tests, and measurements of serum IgE levels, children were phenotyped for the presence of atopic diseases. Genotyping was performed with PCR-based restriction enzyme assays. To assess associations between atopic phenotypes and genotypes standard statistical procedures were applied. RESULTS: Children with the polymorphic allele C2722 had a more than 3-fold risk to develop allergic rhinitis (P <.001) and an almost 2-fold risk for atopic dermatitis (P <.05). Furthermore, the T2104 allele was associated with an almost 2-fold risk for allergic rhinitis (P <.05). When a C insertion at position 3020 was present, the risk of atopy increased by 50% (P <.05) and serum IgE levels were elevated (P <.01). CONCLUSION: The shared genetic background between Crohn's disease and atopy may indicate that an impaired recognition of microbial exposures results in an insufficient downregulation of excessive immune responses, giving rise to either T(H)2 dominated allergies or T(H)1 related Crohn's disease.

Carrier Proteins↗
PubMed2003

Association of tumor necrosis factor gene polymorphisms and prolonged mechanical ventilation after coronary artery bypass surgery.

OBJECTIVE: Prolonged mechanical ventilation is a common complication after coronary artery bypass graft surgery. Tumor necrosis factor alpha is an important proinflammatory mediator in the post-coronary artery bypass graft inflammatory cascade. We attempted to study the effect of polymorphisms at the -308 site in the promoter region of the tumor necrosis factor gene (TNF-308) and the +250 site within the lymphotoxin-alpha gene (LT alpha+250) on the risk of prolonged mechanical ventilation after coronary artery bypass grafting. DESIGN: Prospective observational study. SETTING: Tertiary care center. PATIENTS: A total of 400 patients undergoing coronary artery bypass grafting were enrolled. MEASUREMENTS: The primary end point was time to extubate. Secondary end points were the percentages of patients extubated at 8, 24, and 48 hrs; the length of intensive care unit and hospital stay; the need for a rehabilitation facility; and 30-day mortality. Precollected blood was used for gene analysis. Genotyping was performed by polymerase chain reaction and restriction enzyme digestion. MAIN RESULTS: Patients with an AA genotype at the LT alpha+250 site and those without the LT alpha+250G/-308TNFG haplotype had a shorter duration of mechanical ventilation (11.5 vs. 27.8 hrs and 11.2 vs. 29.4 hrs; =.039 and.01, respectively). The risk of prolonged mechanical ventilation at 8, 24, and 48 hrs was higher for patients with a GA or GG genotype at the LT alpha+250 site and the LT alpha+250G/TNF-308G haplotype. This association between genotype and duration of mechanical ventilation was more dramatic in patients undergoing conventional coronary artery bypass grafting than in those undergoing off-pump coronary artery bypass grafting. With Bayesian analysis, clinical criteria and genotype can be used sequentially to predict the risk of prolonged mechanical ventilation. CONCLUSIONS: The LT alpha+250 and LT alpha+250G/TNF-308G haplotypes are associated with prolonged mechanical ventilation after coronary artery bypass graft. Preoperative genetic screening may guide intraoperative management to reduce postoperative complications.

Bayes Theorem↗
PubMed2002

Risk factors for hepatitis C virus infection among Koreans according to the hepatitis C virus genotype.

To investigate risk factors for HCV infection according to the genotype, we studied 178 patients positive for HCV-PCR and 226 controls that were negative for the anti-HCV antibody. One hundred and twenty five controls (community control) were recruited from spouses of HCV-PCR-positive patients and the other 101 from hospital visitors (hospital control). HCV genotyping was performed by PCR, and epidemiological data were obtained from all participants. The distribution of HCV genotypes was as follows -- 1a (0.6%), 1b (39.9%), 2a (38.2%), 2b (0%), 3 (1.1%), and unclassified (20.2%). By multivariate analysis, blood transfusion (OR 2.90) and endoscopy (OR 2.80) were found to be risk factors for HCV genotype 1b versus the community control. Similarly, blood transfusion (OR 3.17) was found to be risk factors for HCV genotype 1b versus the hospital control. Blood transfusion (OR 2.75) and endoscopy (OR 3.57) were risk factors for HCV genotype 2a versus the community control, and blood transfusion (OR 4.55) and endoscopy (OR 2.16) were those versus the hospital control. Our results suggest that the risk factors for HCV infection are similar among the different genotypes. Blood transfusion and endoscopy were found to be associated with HCV infection.

Female↗
PubMed2001

[Genetic variation of NADPH/NADH oxidase and susceptibility to diffuse panbronchiolitis (DPB) and chronic obstructive pulmonary disease (COPD)].

Diffuse panbronchiolitis (DPB) and chronic obstructive pulmonary disease (COPD) are both characterized by chronic airflow obstruction of unknown etiology. It is hypothesized that neutrophils play the major role in the pathogenesis of these diseases. Recent studies have suggested that genetic factors may be related to individual susceptibility to these diseases. We have investigated the association between the C 242 T polymorphism of p 22 phox, a critical subunit of superoxide-generating NADH/NADPH oxidase, and susceptibility to DPB and COPD. Blood samples obtained from both patients with DPB (n = 82), COPD (n = 53), and control subjects (n = 82) were used for this genotyping assay; and the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were performed to genotype the gene. The frequency of the C allele was 0.91, 0.92, 0.92 in the DPB, COPD, and control groups, respectively. There were no differences in the distribution of the genotype of p 22 phox among these groups, either. We concluded that there is no association between the C 242 T polymorphism of p 22 phox, and susceptibility to DPB and COPD.

Bronchiolitis↗
PubMed2005

[Expression of the symbiotic nod4 pea gene against various genotypic backgrounds].

Experiments on the effect of genotypic environment on the expression of the nod4 gene, responsible for supernodulation in pea, were performed. The genotypic background was found to affect the manifestation of both major symbiosis-related traits (number of nitrogen-fixing bacterial nodules and nitrogenase activity) and productivity-related traits (stem height, seed number, and seed weight), which form the pleiotropic complex of the mutant gene. Using recurrent selection, we developed supernodulating lines significantly exceeding the original mutant line and studied them up to generations F5-F6. Of special importance is the fact that these lines showed high levels of nodulation and nitrogen fixation. The results are discussed from the viewpoint of breeding.

Genes, Plant↗
PubMed2006

HLA alleles in pre-menopausal breast cancer patients from western India.

BACKGROUND & OBJECTIVES: Cytotoxic function of Natural Killer (NK) cells is regulated by the products of HLA class I genes. Associations between HLA alleles and risk for cancers have been suggested earlier. Several reports further emphasize the need to examine influence of HLA genotypes on risk for malignant disorders. Therefore, we undertook this study to assess the possibility of association of HLA-class I alleles in pre-menopausal breast cancer patients. METHODS: Eighty one pre-menopausal breast cancer patients and 160, age and ethnicity matched healthy women from western India were studied. Genotyping for HLA class I alleles and HLA-B*40 alleles (high resolution) was performed using genotyping kits from Genovision Inc., USA. RESULTS: Nearly two-fold higher frequency of HLA - B*40 (16%) was observed in patients compared to controls (O.R. = 2.2; 95% C.I.-1.15-4.34; P<0.02). High resolution typing for HLA-B*40 alleles revealed predominance of HLA-B*4006 allele in both the study groups. Two other important observations relate to lower frequency of HLA - B*08 in patients and homozygosity at HLA-Cw locus in significantly higher proportion of patients. INTERPRETATION & CONCLUSION: The nature of peptides presented by HLA-B*4006 may have implications for higher frequency of HLA-B*40 in breast cancer patients. Higher frequency of homozygosity at HLA-Cw alleles in patients suggests a role for killer immunoglobulin-like receptors (KIRs) in NK cell mediated immune surveillance. Results of this study provide directions to further analyse role of immunogenetic mechanisms governing innate and adaptive immune responses contributing to modulation of risk for breast cancer.

Adult↗
PubMed2002

The effect of age, body mass index, and fasting triglyceride level on postprandial lipemia is dependent on apolipoprotein E polymorphism in subjects with non-insulin-dependent diabetes mellitus.

The aim of this study was to evaluate in non-insulin-dependent diabetes mellitus (NIDDM) subjects the respective influence of apolipoprotein (apo) E polymorphism, age, gender, weight, fasting triglyceride (TG) status, and glycemic status on postprandial lipemia. Apo E genotyping was performed in consecutive NIDDM hospitalized patients in order to recruite size-adjusted groups of each apo E genotype. In 57 NIDDM including 22 E3/3 (E3), 18 E2/3 (E2), and 17 E4/3 (E4) subjects, an 8-hour vitamin A-fat loading test was performed and TG and retinyl palmitate (RP) measured. Fasting TG level correlated with the TG area under the incremental curve (AUIC) (r = 0.512, P <.001) but not with RP AUIC. Despite not different fasting and postprandial TG concentrations, E2 and E4 carriers exhibited a 2- to 3-fold higher RP AUIC than E3 carriers (P =.01). Multivariate analysis indicated an age x apo E interaction on postprandial TG (P <.01), since the unfavorable effect of E2 and E4 allele on TG AUIC was unmasked by aging. In addition, a fasting TG x apo E interaction on postprandial TG was shown (P <.01), and the correlation between fasting TG and TG AUIC was actually restricted to E2 or E4 carriers. Finally, the negative correlation between BMI and postprandial TG observed in the experimental group was actually restricted to E4 carriers (r = -0.77, P <.001). Our results indicate interactions between apo E polymorphism and aging, fasting TG level and BMI that may be important for analyzing postprandial TG clearance in NIDDM.

Aging↗
PubMedDate not supplied

Interpreting resistance data for HIV-1 therapy management--know the limitations.

Antiviral drug resistance can be one of the causes for HIV-1 therapy failure. Several studies have shown some beneficial effect of antiviral resistance testing on response to the following therapy regimen. The technical performances of genotypic and phenotypic assays have been considerably improved with time. However, both are still limited in their power to fully map antiviral resistance as cause of therapy failure. Nevertheless, the results of genotypic and phenotypic assays can often deliver complementary information. The greatest challenge still remains in the accurate interpretation of in vitro resistance results, whether genotypic or phenotypic, into information that can be implemented into clinical practice. For phenotypic assays, bioinformatics analyses linking fold-resistance values and clinical response data have been performed, or are currently ongoing, to assign clinical cut-offs for all drugs. Genotypic drug-resistance interpretation systems have been developed and are continuously being updated to solve the same problem. Retrospective and prospective studies have compared systems in their performance to predict phenotype or in their ability to predict therapy outcome. All these analysis are of value, but still display some weak points. However, due to the fast evolving know-how in the field, a prospective trial in which different systems are compared head-to-head will be difficult to design.

Antiretroviral Therapy, Highly Active↗
PubMed2005

Association of a single nucleotide polymorphism in the matrix metalloproteinase-1 promoter with glioblastoma.

A key feature in the malignant behavior of glioblastoma is the tendency to invade host brain tissue surrounding the primary tumor site. Several members of the matrix metalloproteinase family are thought to contribute to this invasive capacity. A single nucleotide polymorphism has been described in the matrix metalloproteinase-1 (MMP-1) promoter that consists of either the presence or absence of a guanine nucleotide at position -1607. The presence of the guanine base creates a functional binding site for members of the ETS family of transcription factors and has been shown to increase MMP-1 transcription. The purpose of our study was to characterize this polymorphism in human glioblastoma. Promoter genotyping was performed on brain tumor tissue obtained from 81 patients and compared to 57 healthy individuals. The 2G/2G genotype is more prevalent in glioblastoma tissue compared to healthy individuals (p = 0.01). mRNA and protein expression were measured in a subset of brain tumor and normal brain tissue samples. MMP-1 protein levels are significantly higher in glioblastoma tissue compared to normal brain (p = 0.001). Electromobility shift assays and promoter assays were performed to assess binding capability and transcriptional activity, respectively. Proteins present in glioma cell lines can specifically bind the 2G promoter probe. MMP-1 transcription is significantly higher in cells transfected with the 2G promoter when compared to cells transfected with the 1G promoter (p<0.02). This polymorphism may provide a mechanism for increased expression of MMP-1 in malignant gliomas via elevation of MMP-1 mRNA transcription and may underlie the invasive phenotype.

Base Sequence↗
PubMed2004

Molecular epidemiology of hepatitis B, C and D viruses in Turkish patients.

Different genotypes of the hepatitis viruses may influence the clinical outcome of the disease. The distribution of genotypes may vary according to geographical regions. The aim of this study was to evaluate hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV) genotypes in Turkish patients with chronic hepatitis in a large cohort of patients. Genotyping was performed in 41, 59 and 365 patients with chronic hepatitis B, D and C, respectively, and 36 hemodialysis patients with chronic hepatitis C. Genotypes were determined by direct sequencing in hepatitis B and by polymerase chain reaction-restriction fragment length polymorphism in hepatitis C and D patients. In addition, HBV subtyping by multiplex PCR and subtype specific ELISA were performed in 83 and 71 HBsAg (+) blood donors, respectively. All hepatitis B (100%) and hepatitis D (100%) patients had genotype D and type I, respectively. HBsAg subtyping by two methods yielded that 99% of the patients were subtype ayw. S gene amino acid sequence in the 41 patients included for HBV genotyping revealed the ayw2 subtype. Genotype distribution of 365 patients with chronic C hepatitis were as follows: 306 (84%) patients genotype 1b, 43 (11%) patients genotype 1a, 10 (3%) patients genotype 2, 3 (1%) patients genotype 3, 3 (1%) patients genotype 4. Among 36 patients receiving hemodialysis, 28 (78%) patients had genotype 1b and 8 (22%) patients had genotype 1a. The study indicates that Turkish patients with chronic viral hepatitis show very little genotypic heterogeneity. Subtype ayw and the genotype D of HBV DNA, and the type I of HDV RNA represent almost 100% of related infections. The genotype 1b of HCV RNA was found to be significantly dominant in Turkish patients.

Adolescent↗